and millions... are polluting our environment. [ sniffing ] [ seagulls squawking ] >> welcome back to the kron 4 morning news not the very latest on our top story, the attack at the boston marathon, as we take a live look at boston right now. law-enforcement officers have surged an apartment in a boston suburb in the investigation. some investigators are scene early this morning leaving the home in revere, mass., carrying rubber bags, plastic trash bags and a dufflebag. so far, investigators said they did not that anyone under arrest or have a motive in the attack that killed at least three people and wounded more than 140. >> san francisco mayor ed lee assures residents and visitors that san francisco is safe. san francisco is to host a number a big community event that includes the up coming in bay to breakers race on may 19th. the mayor says, security remains a top priority. >> i want to make sure everyone knows public safety is the number-one thing. we have to look at everything with these events and everything that occurred in boston to figure this out. so that will ultimately ma